What is High Frequency?
High Frequency (HF) refers to the range of radio frequency electromagnetic waves falling between 3 and 30 megahertz (MHz), as designated by the International Telecommunication Union (ITU). It is alternatively referred to as the decameter band or decameter wave due to its wavelengths spanning from one to ten decameters (equivalent to ten to one hundred meters). Frequencies immediately below HF are classified as medium frequency (MF), while those above belong to the very high frequency (VHF) band.
Who uses HF?
The HF band finds application in various fields, including international shortwave broadcasting stations (operating within the range of 3.95–25.82 MHz), aviation communication, among others. Forsstrom High Frequency AB utilize HF (operating around 27.12 MHz) to weld thermoplastic materials like PVC and PU. Forsstrom’s customers manufacture a great variety of end products in these materials, such as truck and boat covers, tarps, tents, structures, pool liners, sunshades, billboards, inflatable products, liquid tanks, movie screens, waterbeds, stretch ceilings, valve membranes and oil booms.
Why use High Frequency?
HF-welding is by far the best method for joining PVC and PU materials. The weld is much stronger, compared to other technologies, such as hot air, hot wedge or impulse welding. The resulting weld is also airtight and waterproof.